In revolving flats of carding machines it is known to use so-called clothing strips, on the underside whereof a plurality of clothing needles are fixed in the form of wire hooks. Each clothing strip is fixed to respectively one flat rod by means of so-called clothing clips or clothing clamps, a plurality of flat rods being combined to form a revolving endless chain.
The clothing clips are usually made of metal and comprise a first terminal section for attachment to the flat rod and a second terminal section for attachment to the clothing strip. The general advantage of the clothing clip is that they simplify the attachment and exchange of the clothing strips on the flat rods. In this case, they make a positive and non-positive connection between the clothing strip and the flat rod. The clothing clips are usually used in pairs, so that one or more clothing clips one behind the other provides the corresponding holding force on both sides of the flat rod. The second terminal section usually has teeth which engage in the clothing strips. These teeth thereby make a positive connection with the clothing strip. The first terminal section is further bent when drawing on the clothing and thereby clips around the corresponding part of the flat rod.
Numerous solutions for fixing said clothing clips using expensive assembly tools and/or trained specialist staff are known. These procedures are complex and costly.
It is the object of the present invention to ensure that the clothing clip can be attached and removed simply whilst retaining good holding force. In particular, simple handling by less trained staff should be possible according to the invention.
This object is achieved in a method for fixing a clothing strip on a base surface of a flat rod by means of at least one clothing clip which comprises a first terminal section for attachment to the flat rod and a second terminal section for attachment to the clothing strip, whereby a central section of the at least one clothing clip provided between the first and the second terminal section, is deformed directly before or after the clothing clip has been placed against the flat rod; in a clothing clip for fixing a clothing strip on a base surface of a flat rod comprising a first terminal section for attachment to the flat rod and a second terminal section for attachment to the clothing strip, whereby a central section provided between the first and the second terminal section which is configured in such a manner that it can be deformed, at least in sections, directly before or during placement of the clothing clip against the flat rod; and in a pressing tool for deforming a central section of a clothing clip, whereby the tool comprises at least one pressing strip or a mandrel, which is used to form or further develop a deformation zone in the central section.
The advantages of the invention are in particular that the central section of the clothing clip is deformed to produce the holding force and thereby clamps the clothing strip to the flat rod. Various possibilities for clamping the clothing clip are feasible. The clothing clip can, for example, be slightly deformed in its central section before drawing on and then brought to the final shape through the action of force or energy.
According to a first aspect of the invention, the holding force of the clothing clip can be produced or increased by the formation or further development of a zone located between the two terminal sections, in the central section. Without such a zone, the very large forces known from the prior art would be required for bending the first terminal section of the clothing clip which would require complex and therefore expensive tools which could only be handled by trained specialist staff. Such known tools are frequently operated with compressed air. The invention helps here since relatively weak forces are required to produce or further develop a deformation. In this case, the pressing tool according to the invention deforms the central section in order to produce the required holding force or if a deformation is already present, to further develop this whilst the first and/or the second terminal section of the clothing clip preferably rest against the flat rod or clothing strip in their final position. Such a tool requires little specialist knowledge to operate so that the spinning mill operator can have the clothing strips exchanged by their own staff.
According to said first aspect of the invention, it is particularly advantageous if the central section is deformed in such a manner that this zone comes to rest in a recess of the flat rod. Consequently, the central section can be embodied as rectilinearly flat prior to the plastic deformation, which is advantageous in the production of clothing clips. Only the second terminal section for clamping the clothing strip, and advantageously also the first terminal section, are already bent or formed so that they are offset before the central section is deformed or further deformed according to the invention.
Particularly preferably, the deformation zone lies freely in the recess of the flat rod after the pressing-in. By suitably selecting the pressing-in depth of the clothing clip, the operator of the pressing tool himself is accordingly put in a position where he can select how strong the degree of deformation of the clothing clip with the flat rod should be.
The afore-mentioned hand press which is independent of a fixed compressed air network or other supply lines is preferably operated by means of a built-in pneumatic or hydraulic system or purely mechanically. It is also feasible to have a unit which has a combination of the afore-mentioned operating modes or an operating mode not specified further. The pressing tool is furthermore preferably constructed in such a manner that it can not only be used for producing or further developing a deformation zone but also for fixing or creating the first and/or the second terminal section of the clothing clip on the flat rod or clothing strip. Naturally it is also feasible to use dedicated tools for this purpose but it is advantageous to allocate this double function to the pressing tool (hand press). In particular, the high force required from the prior art for bending the first terminal section need not be applied by the pressing tool since the deformation of the central sections then provides the final clamping.
The pressing tool according to the invention preferably has at least two opposing pressing strips or mandrels which can be aligned with respect to one another or moved towards one another. This configuration makes it possible to deform simultaneously two clothing clips arranged opposite to one another on both sides of a flat rod in order to produce the required holding forces for the clothing clips. In a simpler variant, the pressing tool is merely designed to form a deformation zone on a single clothing clip. It must then be used singly on both sides of the flat rod for each clothing clip.
The pressing tool which preferably has the length of the flat rods to which the clothing clips are fastened, is preferably U-shaped. It can then be delivered to the flat rod and the clothing strip to be arranged at its base surface from below and/or from the side. In the working position, the base leg of the pressing tool is arranged adjacent to the clothing strip. So that the base leg does not damage the clothing needles, preferably at least two elevations directed towards the clothing strip, preferably in the form of webs, are provided on the base leg, their height being at least slightly larger than the length of the clothing needles.
The pressing strips or the mandrels of the pressing tool according to the invention in the U-shaped embodiment are preferably each provided in the two side legs. In this case, the pressing strips or mandrels are each arranged opposite the two recesses of the flat rod.
The aforesaid double function of the pressing tool can be realised if the pressing tool has at least two opposite bending cheeks for creating the first terminal sections of the clothing clips at the U-shaped ends of the device. These bending cheeks are particularly preferably used for creating the first terminal section of the clothing clip before producing the deformation according to the invention to achieve the required holding force. For this purpose, the bending cheeks can be pivotally arranged, for example, at the U-shaped ends of the device. In an alternative, the elements producing the bending are embodied as clamping arms capable of translational movement, whereby they create the first terminal section of the clothing clip by a longitudinal advance.
The bending cheeks can preferably be locked in the end position, i.e. after creating the first terminal sections of the clothing clips so that the first terminal sections cannot bend again during the formation of the deformation zone according to the invention for producing the holding force. The second terminal section is preferably firmly inserted in the clothing strip.
Preferably, the same pressing tool as was used for fastening is used to release the at least one clothing clip after the clothing needle tips have worn. Appropriately in this case, the bending cheeks are brought from their clamping position into a release position in order to more strongly deform the respective central section by means of the mandrels or pressing strips, whereby the first terminal sections of the clothing clips open until they can be released from the flat rod manually or, for example, using tongs. Accordingly, the pressing tool according to the invention can take on another function.
According to a second aspect of the invention, the clothing clip according to the invention has at least one central section made of a bimetal whose different expansion properties at different temperatures is used. For this purpose, during application of the clothing clip, the central section is brought to a temperature at which the clothing clip can be simply placed on the flat rod or clothing strip. If the temperature of the bimetal then changes to the stand or operating temperature of the relevant textile machine, the bimetal of the central section contracts and provides the holding force of the clothing clip on the flat rod.
In a particularly preferred embodiment of this method according to the invention, the temperature on application of the clothing clip is raised compared with the operating temperature by means of a hot air device, or similar, so that the preferably convexly (relative to the flat rod) formed central section opens out and the clothing clip can then be brought into its rest position on the flat rod. The bimetal section can then be cooled so that this can again contract into its clamping position and thus the clothing strip is held firmly by means of the clothing clip on the flat rod.
Preferably before pulling on the clothing, the second terminal section of the clothing clip is anchored with its toothed structure in the clothing strip so that during or shortly after heating the bimetal strip, the upper end of the clothing clip can be pivoted towards the flat rod before then contracting during cooling and thereby producing the necessary holding force.
The corresponding clothing clip according to the second aspect of the invention preferably consists of a plurality of separate partial sections, where preferably at least the first partial section is made of a bimetal. This bimetal partial section can preferably be brought into engagement with the flat rod. A second partial section of the clothing clip is preferably connected to the clothing strip in a suitable manner. The two partial sections are preferably connected to one another by means of a detachable hook fastening or in some other suitable manner.
Accordingly, it is advantageous if the second partial section is initially anchored with its offset end in the clothing strip, then its other end is hooked to the first partial section and then the bimetal central section is heated. Then the entire clothing clip consisting of the two partial sections can be pivoted towards the flat rod, the free terminal section of the first partial section preferably embracing an undercut on the flat rod. After the bimetal has cooled, this contracts, whereby the clothing clip firmly clamps the clothing strip on the flat rod.
Advantageous further developments of the invention are characterised by the features of the dependent claims.